Maximizing Contamination Control With Vacuum Technology Clean rooms, as well as any modular environment where attempts are made to keep air borne contaminants, temperature, relative humidity,differential pressure, static electricity and other factors under strict control, come in many shapes and sizes. Whether discussing hard- or soft walled or any of the other types of clean room, one thing is certain – it is virtually impossible to construct and maintain a completely contaminant-free environment, as long as personnel are working in it.